.NET Standard library output doesn't include nuget dependencies

Question

I have these three projects:

An ASP.NET Core MVC application (targeting .NET Framework 4.6.2)
A class library containing my EF Core Models, Migrations and DbContext classes (targeting .NET Standard 2.0, previously .NET Framework 4.6.2).
A console application for updating a database using EF Core Migrations (targeting .NET Framework 4.6.2).

Both 1 and 3 reference 2. I just replaced the old .NET Framework class library with a new one targeting .NET Standard. The class library uses the Microsoft.EntityFrameworkCore.Proxies NuGet package.

Everything builds without error, my unit tests all run, and the ASP.NET Core app runs without issue. My problem is that the console application for updating the database builds, runs, but encounters a runtime error when it initializes the DbContext on this line in the constructor:

ChangeTracker.LazyLoadingEnabled = false;

Saying that it cannot load the assembly Microsoft.EntityFrameworkCore.Proxies. On investigation I found that the Microsoft.EntityFrameworkCore.Proxies.dll file was not in the build output of the console application or the class library project. The only .dll in the output of the class library project was the project .dll itself, the old .NET Framework version had all the NuGet package .dlls in the output as well, and it ran fine using the database update tool.

Is there something extra that is necessary to include the dependencies in the output of a .NET Standard library?

score 6 · Answer 1 · answered Jan 10 '20 at 12:49

6

Here is another suggestion, taken from CEZARY PIĄTEK's blog

 <Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>    
  </PropertyGroup>
</Project>

answered Jan 10 '20 at 12:49

Teo Bebekis

625
8
9

This worked for me, 2.1, I would love to know if anyone has a visual/GUI way of doing the same thing? There's a more indepth chat at https://stackoverflow.com/questions/43837638/how-do-i-get-net-core-projects-to-copy-nuget-references-to-the-build-output – Tyeth Feb 03 '21 at 19:50
This doesn't work after referencing the project in .Net Framework MVC application. It gives System.PlatformNotSupportedException. – prem Sep 27 '21 at 11:53

score 3 · Accepted Answer · answered Feb 11 '19 at 15:53

3

I ended up having to add .NET Framework 4.6.2 to the list of Target Frameworks for the class library.

In .csproj:

<PropertyGroup>
  <TargetFrameworks>netstandard2.0;net462</TargetFrameworks>
</PropertyGroup>

After this it works with a .NET Framework application.

answered Feb 11 '19 at 15:53

Valuator

3,262
2
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The newer answer does what's needed by including all the dll dependencies without messing with the framework version. This should no longer be the accepted answer IMHO – Tyeth Feb 03 '21 at 19:49
1

It works after adding the .Net standard project reference in .Net Framework MVC application whereas the newer answer gives System.PlatformNotSupportedException. Wasted the entire day to debug this issue and finally this answer worked. Thanks for sharing. – prem Sep 27 '21 at 11:56

score 1 · Answer 3 · answered Feb 06 '19 at 19:42

You might have to directly refer to something within that library to ensure the dependency walker sees types in there.

We actually needed to do with sometimes with Entity Framework SQL server at one point

private static readonly [proxylibnamespace].[somepublictype] _ProxyLibReference;

By doing that, sometimes the dependency walker sees a direct reference to a type and then includes it in a final build.

.NET Standard library output doesn't include nuget dependencies

3 Answers3